Fuel cap causing staling after re-fueling? [Archive]

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GARY PAGE

10-25-2003, 17:15

Fuel cap causing staling after re-fueling?

The truck ran without a miss for 50 miles after cleaning all the grounds. I was at a

catmandoo

10-25-2003, 17:29

should be pressure.at least mine always has pressure.

tom.mcinerney

10-25-2003, 18:01

Gary-use the search feature for 'fuel cap'; read at least the topic begun by James Springate (10/11/03) , 'fuel cap hiss'.
If you shut down the engine while fueling, the symptom more like 'warm start, stall' , where clogged fuel filter, bad 'gas cap' , lift pump feeds, get related to worse electric probs. And if left idling, raises question if OPS intermittent at idle as reported in the 'blast from past, OPS fix' topic #3 above....

whatnot

10-25-2003, 20:15

If you have pressure, it is ok. If you have vacuum, you need to replace the fuel cap as soon as possible.

StephenA

10-26-2003, 06:15

Wipe off the cap & suck on the threaded end. No air equals clogged cap. :eek: Leave off until replaced or fuel tank & lines lines will collapse.

G B Sisson

10-26-2003, 18:44

I always have a vaccuum Hiss when I refuel. Is this not supposed to sound like this? ...Maybe it was'nt the PMD.... I will go out now and suck on my fuel cap..Good thing I dont have any neighbors! Gary

G B Sisson

10-26-2003, 18:49

Well I got air thru it sounds like a valve is vibrating. Sounds like "Flipper" on the old TV show...now I have Diesel breath so it was the PMD Good thing Im a bachelor !

norm

10-27-2003, 03:40

I put new cap on a while ago (Stant I think) and had vacuum for some time before I read forum and discovered that was not good. Lucky no collapse. Stant only had this one listing for trucks with diesel or gas engines, so its probably wrong. I'm running a quick fill cap now that can't hold any vacuum. Is there a definite cap where there is no question it will work?

catmandoo

10-27-2003, 05:27

to be sure probably right thru gm.

StephenA

10-27-2003, 06:41

I replaced my factory cap with Stant # 11819 for $6.99 at Checkers. I'm pretty sure Stant makes the caps for GM. This cap is a "Pre-vent" version which lets the pressure out at the first half turn. There is some resistance to letting air in on both the factory & Stant caps, but not enough to keep air from being sucked in easily on testing.

GARY PAGE

10-27-2003, 16:41

Was a long shot and it wasn't the stalling issue.

StephenA

10-27-2003, 17:57

Is the OPS/lift pump functioning ok?